Question

Solve the equation by factoring. x2+6x-16=0

Answer 1

Answer:

x = 2 or x = -8   (d)

Step-by-step explanation:

Find two factors of 16 which differ by 6. The pair 8,2 works in that 8 × 2 = 16 and 8 - 2 = 6.

Hence we find:

$0 = x^2+6x-16 = (x+8)(x-2)$

So x = 2 or x = -8

Alternatively, complete the square then use the difference of squares identity:

$a^2-b^2 = (a-b)(a+b)$

with $a = (x+3)$ and $b=5$ as follows:
$0 = x^2+6x-16$

$=(x+3)^2-9-16$

$=(x+3)^2-25$

$=(x+3)^2-5^2$$=((x+3)-5)((x+3)+5)$

$=(x-2)(x+8)$

Hence zeros $x=2$ and $x=-8$

Subjects:

Algebra  Quadratic Equations and Functions  Comparing Methods for Solving Quadratics

Answer 2

Answer:

hi dear, the answer is option D, {-8,2}